The present invention relates to a tray made of paperboard, or of ovenboard, if it is desired to use the tray for cooking in microwave ovens, and, in particular, to a tray that is collapsible and which, in its collapsed state, can be folded to form an enclosed carton.
In many cases it is desirable to have an open tray formed of paperboard, or ovenboard, from a tray blank which, if desired, could be collapsed and so folded that it becomes an enclosed carton. Such a case may occur where it may be desirable to package and ship a product in an enclosed carton which, after being received by the consumer, may be opened and unfolded in order to remove the contents, thus forming a tray in which the contents can be replaced, and the entire tray and its contents placed in the microwave oven for the necessary heating or cooking. In such case, the blank from which the tray is made would have to be of ovenboard to withstand the heat encountered in the microwave oven.
In other instances, however, it may be desirable to package a product and enclose it in the carton and ship it to the consumer who, upon receiving the enclosed carton, may prepare the contents thereof for use and then simply serve it or eat it from the tray which is formed when the carton is unfolded.
Most of the foods which are to be cooked in microwave ovens today come in a package from which they must be removed and placed in a second package which can be utilized in microwave ovens. Such a procedure is, of course, expensive because it requires two cartons in which to ship and to cook the product. In addition, it may even be necessary to remove the heated contents from the tray and serve it in an additional container. This would require three separate containers.
The present invention overcomes the disadvantage of the prior art by providing an enclosed carton in which the product may be shipped and sold to the consumer but which, upon receipt by the consumer, may be opened and unfolded to form a tray in which the product carried therein may be mixed and or cooked in the microwave oven and/or served. In such case, of course, as stated earlier, the material from which the collapsible tray is formed must be of a type that can withstand the heat generated in a microwave oven. An example of such a material is ovenboard.
In the prior art, one piece cartons are known which assume a tray-like configuration during intermediate stages of the erection operation. One example of such a carton can be found in U.S. Pat. No. 4,191,323, issued Mar. 4, 1980 to Webinger. The tray-like configuration facilitates loading of a product into the carton before it is sealed. However, since the latter carton is not intended to be used for cooking, the tray-like configuration is not continuous or sealed and therefore is incapable of functioning in suitable manner. Further, the tray-like configuration of the latter carton does not have the rigidity necessary to withstand the handling associated with a cooking operation.
Thus, it is an object of the present invention to provide a collapsible, yet structurally rigid tray into which a product may be placed, the tray folded to form an enclosed carton in which the product may be shipped and sold to a consumer and then unfolded to reform the tray in which the product may be either cooked or served or stored.